U.S. patent application number 11/058006 was filed with the patent office on 2006-04-27 for polymeric colorants having pigment and dye components and corresponding ink compositions.
Invention is credited to Sundar Vasudevan.
Application Number | 20060089421 11/058006 |
Document ID | / |
Family ID | 35604581 |
Filed Date | 2006-04-27 |
United States Patent
Application |
20060089421 |
Kind Code |
A1 |
Vasudevan; Sundar |
April 27, 2006 |
Polymeric colorants having pigment and dye components and
corresponding ink compositions
Abstract
Colorants having pigment and dye components having improved
chroma and good water and lightfastness are disclosed and
described. A polymeric colorant can include a pigment having a
polymer covalently attached thereto and a dye covalently attached
to the polymer. A dispersant can be covalently attached to at least
one of the pigment, the polymer, and the dye. By including both a
pigment and a dye component in the polymeric colorant, improved
chroma, waterfastness, and lightfastness can be realized. The dye
and pigment components can be substantially the same color, or can
have different colors, depending on the desired appearance. The
polymeric colorants of the present invention are well suited to
inclusion in ink-jet compositions, although many other applications
are considered suitable for the instant polymeric colorants.
Inventors: |
Vasudevan; Sundar;
(Corvallis, OR) |
Correspondence
Address: |
HEWLETT PACKARD COMPANY
P O BOX 272400, 3404 E. HARMONY ROAD
INTELLECTUAL PROPERTY ADMINISTRATION
FORT COLLINS
CO
80527-2400
US
|
Family ID: |
35604581 |
Appl. No.: |
11/058006 |
Filed: |
February 14, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60622276 |
Oct 25, 2004 |
|
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|
Current U.S.
Class: |
523/160 ;
523/161 |
Current CPC
Class: |
C09B 69/10 20130101;
C09D 11/322 20130101; C09B 68/44 20130101; C09B 68/20 20130101;
C09D 11/30 20130101 |
Class at
Publication: |
523/160 ;
523/161 |
International
Class: |
C03C 17/00 20060101
C03C017/00; C09D 11/00 20060101 C09D011/00 |
Claims
1. A polymeric colorant, comprising: a) a pigment having a polymer
covalently attached thereto; b) a first dye covalently attached to
the polymer; and c) a dispersant covalently attached to at least
one of the pigment, the polymer, and the first dye.
2. The colorant of claim 1, wherein the polymer is a member
selected from the group consisting of maleic anhydride copolymers,
acrylic copolymers, methacrylic copolymers, amine or
alcohol-containing copolymers, and combinations thereof.
3. The colorant of claim 2, wherein the polymer is a maleic
anhydride copolymer.
4. The colorant of claim 3, wherein the polymer is selected from
the group consisting of styrene-maleic anhydride copolymer, methyl
vinyl ether-maleic anhydride copolymer, vinyl pyrrolidone-maleic
anhydride copolymer, styrene acrylic acid copolymer, styrene
methacrylic acid copolymer, 4-vinylaniline-acrylic acid copolymer,
4-vinylaniline-methacrylic acid copolymer, and combinations
thereof.
5. The colorant of claim 1, wherein the polymer is attached to the
pigment through a linking group.
6. The colorant of claim 5, wherein the linking group is a member
selected from the group consisting of 2-(4-aminophenyl)
sulfonylethane sulfonate, 4-aminobenzylamine, 4-aminophenylalanine,
and combinations thereof.
7. The colorant of claim 1, wherein the first dye is selected from
the group consisting of C.I. Acid Red 440, C.I. Reactive Red 3,
C.I. Reactive Red 13, C.I. Reactive Red 23, C.I. Reactive Red 24,
C.I. Reactive Red 33, C.I. Reactive Red 43, C.I. Reactive Red 45,
C.I. Reactive Red 120, C.I. Reactive Red 180, C.I. Reactive Red
194, C.I. Reactive Red 220, C.I. Reactive Violet 4, C.I. Reactive
Blue 19, C.I. Reactive Blue 5, C.I. Reactive Blue 49, C.I. Reactive
Yellow 2, C.I. Reactive Yellow 3, C.I. Reactive Black 39, and
combinations thereof.
8. The colorant of claim 1, further comprising a second dye
covalently attached to the polymer.
9. The colorant of claim 8, wherein the second dye is a different
color than the first dye.
10. The colorant of claim 1, wherein the pigment is a different
color than the first dye.
11. The colorant of claim 10, wherein the pigment has a black color
and the first dye has a cyan or magenta color such that the
polymeric colorant has an effective color which is a neutral
gray.
12. The colorant of claim 1, wherein the pigment is a member
selected from the group consisting of black pigments, cyan
pigments, magenta pigments, and yellow pigments.
13. The colorant of claim 12, wherein the pigment is carbon
black.
14. The colorant of claim 1, wherein the dispersant is attached to
the pigment.
15. The colorant of claim 1, wherein the dispersant is attached to
the polymer.
16. The colorant of claim 1, wherein the dispersant is a member
selected from the group consisting of polyalkyl glycols, polyalkyl
imines, trehalose, acrylates, methacrylates, and combinations
thereof.
17. The colorant of claim 1, wherein the polymeric colorant has a
ratio of dye molecules per weight of pigment particle from about 10
.mu.mole per gram to about 100 mmole per gram.
18. The colorant of claim 1, further comprising a stabilizing
additive.
19. The colorant of claim 1, wherein the polymeric colorant has the
general structure: ##STR3## where x, y, and z are non-zero positive
integers such that the polymeric colorant has a molecular weight
less than about 20,000; R1 is the first dye, the dispersant, or a
linking group attached to the pigment with the proviso that z is at
least three and at least one of each of the first dye, the
dispersant, and the linking group is present; and R2 is a
hydrophobic group.
20. The colorant of claim 19, wherein the polymeric colorant has
the general structure: ##STR4## where a, b, and c are non-zero
positive integers such that the polymeric colorant has a molecular
weight less than about 20,000.
21. An ink-jet ink composition, comprising a liquid vehicle having
a polymeric colorant dispersed therein, said polymeric colorant
including: a) a pigment having a polymer covalently attached
thereto; b) a dye covalently attached to the polymer; and c) a
dispersant covalently attached to at least one of the pigment, the
polymer, and the dye.
22. The composition of claim 21, wherein the polymer is a maleic
anhydride copolymer.
23. The composition of claim 21, wherein the polymer is attached to
the pigment through a linking group.
24. The composition of claim 21, wherein the dye has a reactive
group selected from the group consisting of hydroxy, amino,
carboxylic acid, sulfonic acid, thiol, halotriazine, maleimide
sulfone, vinyl sulfone, and combinations thereof.
25. The composition of claim 21, wherein the dispersant is attached
to the pigment.
26. The composition of claim 21, wherein the dispersant is attached
to the polymer.
27. An ink-jet ink composition, comprising: a) a liquid vehicle; b)
a polymer attached dye including a dye covalently attached to a
polymer, said dye having a first color; and c) a pigment having a
second color which has a substantially different hue from the first
color.
28. The composition of claim 27, wherein the pigment is
polymer-dispersed.
29. The composition of claim 27, wherein the pigment is covalently
attached to the polymer to form a polymeric colorant.
30. The composition of claim 27, further comprising at least two
different dyes covalently attached to the polymer.
31. The composition of claim 27, wherein the first color is cyan,
magenta, or yellow and the second color is black.
32. The composition of claim 31, wherein the first color is cyan or
magenta such that the ink-jet ink composition has an effective
color of neutral gray.
33. The composition of claim 27, wherein the polymer is selected
from the group consisting of maleic anhydride copolymers, acrylic
copolymers, methacrylic copolymers, amine or alcohol-containing
copolymers, and combinations thereof.
34. The composition of claim 27, wherein the dye has a reactive
group selected from the group consisting of hydroxy, amino,
carboxylic acid, sulfonic acid, thiol, halotriazine, maleimide
sulfone, vinyl sulfone, and combinations thereof.
35. A method of forming a polymeric colorant, comprising the steps
of: a) attaching a dye to a polymer to form a polymer-dye colorant;
b) attaching the polymer to a pigment; and c) attaching a
dispersant to at least one of the polymer-dye colorant and the
pigment.
36. The method of claim 35, wherein said dye has a reactive group
selected from the group consisting of hydroxyl, amino, carboxylic
acid, sulfonic acid, thiol, halotriazine, maleimide sulfone, vinyl
sulfone, and combinations thereof.
37. The method of claim 36, wherein said polymer includes an
anhydride group configured for reaction with the reactive
group.
38. The method of claim 35, wherein the polymer is a maleic
anhydride copolymer.
39. The method of claim 35, wherein the polymer is attached to the
pigment through a linking group.
40. The method of claim 35, wherein the dye is selected from the
group consisting of C.I. Acid Red 440, C.I. Reactive Red 3, C.I.
Reactive Red 13, C.I. Reactive Red 23, C.I. Reactive Red 24, C.I.
Reactive Red 33, C.I. Reactive Red 43, C.I. Reactive Red 45, C.I.
Reactive Red 120, C.I. Reactive Red 180, C.I. Reactive Red 194,
C.I. Reactive Red 220, C.I. Reactive Violet 4, C.I. Reactive Blue
19, C.I. Reactive Blue 5, C.I. Reactive Blue 49, C.I. Reactive
Yellow 2, C.I. Reactive Yellow 3, C.I. Reactive Black 39, and
combinations thereof.
41. The method of claim 35, wherein the pigment is a member
selected from the group consisting of black pigments, cyan
pigments, magenta pigments, and yellow pigments.
42. The method of claim 35, wherein the dispersant is attached to
the polymer or the pigment prior to attaching the dye to the
polymer.
43. The method of claim 35, wherein the dye is attached to the
polymer prior to attaching the polymer to the pigment.
44. The method of claim 35, wherein the dispersant is a member
selected from the group consisting of polyalkyl glycols, polyalkyl
imines, trehalose, acrylates, methacrylates, and combinations
thereof.
45. The method of claim 35, wherein the polymeric colorant has the
general structure: ##STR5## where x, y, and z are non-zero positive
integers such that the polymeric colorant has a molecular weight
less than about 20,000; R1 is the dye, the dispersant, or a linking
group attached to the pigment with the proviso that z is greater
than three and at least one of each of the dye, the dispersant, and
the linking group is present; and R2 is a hydrophobic group.
Description
CLAIM OF PRIORITY
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/622,276, filed on Oct. 25, 2004, which is
incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to colorants and
methods of making such colorants. More particularly, the present
invention relates to compositions including both pigment and dye
components.
BACKGROUND OF THE INVENTION
[0003] Colorants are widely used in many applications to provide
useful and aesthetic appearance to articles and printed images.
Standard colorants can most often be classified as either pigments
or dyes. Although such colorants can be directly mixed into an
article of manufacture, it is often desirable to prepare ink
compositions containing colorants for printing of color images.
Such ink compositions typically include a liquid vehicle such as an
appropriate solvent containing the dye or the pigment. Dye-based
inks generally use a colorant that is soluble in the given liquid
vehicle. Conversely, pigmented inks typically use an insoluble
dispersed solid colorant to achieve color.
[0004] Dye and pigment colorants each have certain properties which
are beneficial in certain circumstances and can provide
predetermined color properties to a printed image. However, each of
dye and pigment colorants also have various limitations and
drawbacks which present unique challenges. Specifically, dye
colorants exhibit good chroma and long-term stability in solution.
However, dye colorants also tend to have poor waterfastness,
lightfastness, and smear resistance. In contrast, pigment colorants
typically have good waterfastness, good lightfastness, and good
smear resistance. Unfortunately, pigment colorants also tend to
have limited chroma and a myriad of issues related to maintaining
the pigment particles dispersed in solution. Thus, pigment
particles of pigment inks can often settle over time.
[0005] Thus, the choice of dye and pigment colorants for use in any
particular application is often constrained to these limitations
and a wide variety of chemical and physical mechanisms are used to
minimize these constraints in a particular commercial product.
Accordingly, investigations continue into developing colorants and
ink formulations that have improved properties which reduce the
above-mentioned limitations.
SUMMARY OF THE INVENTION
[0006] It has been recognized that it would be advantageous to
develop colorants which have both improved chroma and good
waterfastness and lightfastness which are suitable for use in a
variety of inks.
[0007] In one aspect of the present invention, a polymeric colorant
can include a pigment having a polymer covalently attached thereto.
Further, a dye can be covalently attached to the polymer.
Additionally, a dispersant can be covalently attached to at least
one of the pigment, the polymer, and the dye.
[0008] Alternatively, an ink-jet ink composition can include a
liquid vehicle, a polymer attached dye, and a pigment. The polymer
attached dye can include a dye covalently attached to a
polymer.
[0009] Additional features and advantages of the invention will be
apparent from the following detailed description which illustrates,
by way of example, features of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0010] Before particular embodiments of the present invention are
disclosed and described, it is to be understood that this invention
is not limited to the particular process and materials disclosed
herein, as such may vary to some degree. It is also to be
understood that the terminology used herein is used for the purpose
of describing particular embodiments only and is not intended to be
limiting, as the scope of the present invention will be defined
only by the appended claims and equivalents thereof.
[0011] In describing and claiming the present invention, the
following terminology will be used.
[0012] The singular forms "a," "an," and "the" include plural
referents unless the context clearly dictates otherwise. Thus, for
example, reference to "a dye" includes reference to one or more of
such materials.
[0013] As used herein, "vehicle" is defined to include liquid
compositions that can be used to carry colorants to a substrate.
Liquid vehicles are well known in the art, and a wide variety of
ink vehicles can be used in accordance with embodiments of the
present invention. Such ink vehicles can include a mixture of a
variety of different agents, including without limitation,
surfactants, solvents, co-solvents, buffers, biocides, viscosity
modifiers, sequestering agents, stabilizing agents, and water. The
liquid vehicle can also carry other additives such as polymers, UV
curable materials, plasticizers, and/or cosolvents in some
embodiments.
[0014] As used herein, "pigment" refers to a colorant particle
which is substantially insoluble in the liquid vehicle in which it
is used.
[0015] As used herein, "dye" refers to a colorant compound which is
substantially soluble in the liquid vehicle in which it is
used.
[0016] As used herein, "functionalized" refers to pigment particles
which have a compound chemically attached via covalent bonds. This
is in contrast to pigment particles which have compounds attached
via ionic bonds or other weaker intermolecular forces.
[0017] As used herein, "bleed" refers to the tendency of ink to run
into and mix with adjacently printed inks. Bleed typically occurs
prior to adjacently printed inks fully drying on a substrate. The
degree of bleed will depend on a variety of factors such as the
drying speed of the ink, ink chemistry, i.e. the presence of
reactive or non-reactive bleed control mechanisms, and type of
substrate, among other variables.
[0018] As used herein, "waterfastness" refers to an ink's exhibited
degree of water resistance after printing on a substrate.
Typically, this property is measured after the ink has dried, and
measures the tendency of the ink to smear or otherwise change
location in the presence of moisture.
[0019] As used herein, "chroma" refers to the attribute of color
used to indicate the degree of departure of the color from gray of
the same lightness as defined by ASTM (ASTM E 284). It is also used
to refer to degree of saturation of color which is the ratio of
chroma over lightness (C*/L*). Typically, dye colorants have a
greater degree of saturation over pigment colorants having the
same, or substantially the same, hue.
[0020] As used herein, "neutral gray" refers to a shade of gray
which exhibits a substantial color constancy, i.e. substantially no
change in color appearance when viewed under different light
sources such as fluorescent light and sunlight. Further,
non-neutral gray colors also tend to have a subtle red or brown
shade or appearance.
[0021] As used herein, the term "reactive" when referring to ink
sets refers to a chemical reaction between two or more ink-jet
inks. Such reactive ink sets can interact either by salt
mechanisms, pH differential mechanisms, polymerization mechanisms,
or other reactive mechanisms known to those skilled in the art.
[0022] As used herein, "self-dispersed pigment" refers to pigments
that have been functionalized with dispersing agent, such as by
chemical attachment or attraction of the dispersing agent to the
surface of the pigment. The dispersing agent can be a small
molecule or a polymer.
[0023] As used herein, "polymer-dispersed pigment" refers to a type
of self-dispersed pigment wherein the pigment is attached to or is
at least partially encapsulated by a polymer. The polymer can be
covalently attached to the pigment surface, either directly or via
an intermediate attachment group, or can be attached through
non-covalent intermolecular attractive forces.
[0024] As used herein with respect to an identified property or
circumstance, "substantially the same" allows for a degree of
deviation that is sufficiently small so as to not measurably or
visibly detract from the identified property or circumstance. The
exact degree of deviation allowable may in some cases depend on the
specific context. Thus, for example, a colorant which has a color
"substantially" that of another colorant may deviate in color, i.e.
hue, or other relevant property within a range which is
imperceptible or nearly imperceptible upon visual inspection. Of
course, other properties can vary considerably. For example, a
black pigment can have substantially the same color and hue as a
black dye; however, chroma, optical density, gloss, solubility, and
the like can differ dramatically from one another. Conversely,
identification of a property which is "substantially different"
indicates a visible and/or measurable degree of difference.
[0025] Concentrations, amounts, and other numerical data may be
presented herein in a range format. It is to be understood that
such range format is used merely for convenience and brevity and
should be interpreted flexibly to include not only the numerical
values explicitly recited as the limits of the range, but also to
include all the individual numerical values or sub-ranges
encompassed within that range as if each numerical value and
sub-range is explicitly recited. For example, a weight range of
about 1% to about 20% should be interpreted to include not only the
explicitly recited concentration limits of 1% to about 20%, but
also to include individual concentrations such as 2%, 3%, 4%, and
sub-ranges such as 5% to 15%, 10% to 20%, etc.
[0026] In accordance with the present invention, a polymeric
colorant can include a pigment having a polymer covalently attached
thereto. Further, a dye can be covalently attached to the polymer.
A dispersant can be covalently attached to at least one of the
pigment, the polymer, and the dye to provide dispersion stability
to the polymeric colorant in a liquid vehicle. By including both a
pigment and a dye component, the polymeric colorant can benefit
from the properties of each. The dye and pigment components can be
substantially the same color, or can be of different colors,
depending on the desired appearance. The polymeric colorants of the
present invention are well suited to inclusion in ink-jet
compositions, although many other applications are considered
suitable for the instant polymeric colorants.
[0027] Alternatively, an ink-jet ink composition can include a
liquid vehicle, a polymer attached dye, and a pigment. The polymer
attached dye can include a dye covalently attached to a polymer,
with the dye having a first color. Further, the pigment can have a
second color which is substantially different in hue from the first
color. In this alternative aspect, the pigment can be
self-dispersed, polymer-dispersed, or covalently attached to the
polymer.
Polymeric Colorants
[0028] The polymeric colorants of the present invention can include
a wide variety of polymers which can be covalently attached to dyes
and/or pigments in accordance with the principles described herein.
Polymers containing a reactive group such as anhydrides, carboxylic
acids, sulfonic acids, vinyl sulfones, amines, alcohols, thiols, or
the like are exemplary of suitable polymers. Non-limiting examples
of specific polymers which can be used include maleic anhydride
copolymers, acrylic copolymers, methacrylic copolymers, amine or
alcohol-containing copolymers, and combinations thereof. In one
aspect, the polymer can include an anhydride group configured for
reaction with the reactive group of the dye. In another aspect, the
polymer can include a carboxylic acid group which can serve as a
point of attachment for the dye and optional additional groups,
e.g., linking groups, lightfastness enhancing groups, dispersants,
and the like.
[0029] In one aspect, suitable polymers can include, but are not
limited to, styrene-maleic anhydride copolymer, methyl vinyl
ether-maleic anhydride copolymer, vinyl pyrrolidone-maleic
anhydride copolymer, styrene acrylic acid copolymer, styrene
methacrylic acid copolymer, 4-vinylaniline-acrylic acid copolymer,
4-vinylaniline-methacrylic acid copolymer, and combinations
thereof. In one specific aspect of the present invention, the
polymer can be a maleic anhydride copolymer such as, but not
limited to, styrene-maleic anhydride copolymer, methyl vinyl
ether-maleic anhydride copolymer, vinyl pyrrolidone-maleic
anhydride copolymer, and combinations thereof. One polymer which
has proven particularly useful is styrene maleic anhydride
copolymer (SMA). Other specific polymers can include
styrene-acrylics, polyethylene imine/phthalic anhydrides,
polyethylene imine/phenylsuccinic anhydrides, polyethylene
imine/succinic anhydrides, pentaethylene hexamines, polyethylene
imines, polyurethanes, polyureas, acrylic polymers, vinyl polymers,
polypyrrolidones, epoxies, polyesters, polysaccharides,
polypeptides, celluloses, polyquaternary amines, polyamines, and
copolymers thereof. Further, polymers capable of dispersing
pigments at near neutral pH such as those containing sulfonic
acids, fluoric acids, and .alpha.- and/or .beta.-fluorocarboxylic
acids. Several specific examples of such polymers can include
styrene-vinylsulfonic acid copolymers, styrene-butyl
acrylate-methacrylic acid-vinylsulfonic acid copolymers,
styrene-trifluoroacrylic acid-vinylsulfonic acid copolymers,
styrene-.alpha.-(trifluoromethyl)acrylic acid-vinylsulfonic acid
copolymers, styrene-trifluoro acrylic acid copolymers, and the
like.
[0030] The polymeric colorants of the present invention can include
a dye which is covalently attached to the polymer. In one aspect,
the dye can be covalently attached to the polymer prior to
attachment to the pigment, although this is not required. Suitable
dyes can have an active group which can be reacted to form bonds
with a particular polymer to form a polymer-dye colorant. A number
of dyes can be suitable for this purpose. Particularly, dyes having
active groups such as hydroxy, amine, carboxylic acid, sulfonic
acid, thiol, halotriazine, maleimide and vinyl sulfone, and
combinations thereof can readily form covalent bonds with suitable
polymers. Alternatively, dyes having active groups such as
carboxyl, sulfonyl, or the like can be reacted with polymers having
amino or hydroxyl groups. Thus, the reactive and active groups
mentioned above can be present in either the dye or the polymer,
depending on a specific embodiment. The dyes and the polymers can
also include other functional groups that can be readily converted
to any of the above mentioned groups so that the dye and polymer
can be coupled after such conversion. Those skilled in the art will
recognize various coupling reactions and associated reactive groups
necessary to couple a wide variety of dyes and polymers. In one
specific aspect, dyes having aliphatic amine active groups can be
readily attached to polymers having anhydride, carboxyl, sulfonyl,
and similar groups. Non-limiting examples of suitable dyes can
include food dyes, FD&C dyes, acid dyes, direct dyes, reactive
dyes, phthalocyanine dyes, derivatives of phthalocyanine sulfonic
acids, and combinations thereof. Several specific examples of
suitable dyes can include C.I. Acid Red 440, C.I. Reactive Red 3,
C.I. Reactive Red 13, C.I. Reactive Red 23, C.I. Reactive Red 24,
C.I. Reactive Red 33, C.I. Reactive Red 43, C.I. Reactive Red 45,
C.I. Reactive Red 120, C.I. Reactive Red 180, C.I. Reactive Red
194, C.I. Reactive Red 220, C.I. Reactive Violet 4, C.I. Reactive
Blue 19, C.I. Reactive Blue 5, C.I. Reactive Blue 49, C.I. Reactive
Yellow 2, C.I. Reactive Yellow 3, C.I. Reactive Black 39, and
combinations thereof.
[0031] Further, dyes having active groups such as alcohols and
aromatic amines tend to not be very nucleophilic. Therefore,
attachment of the dye to the polymer can be enhanced by addition of
a nucleophilic catalyst such as, but not limited to,
dimethylaminopyridine, N-methylimidazole, and the like.
Additionally, reactive dyes such as those having vinyl sulfone
groups can be attached via a dye linking group such as a thiol,
e.g., using Michael addition chemistry as known to those skilled in
the art. For example, 2-aminoethanethiol can be reacted with a
polymer having an anhydride or other reactive group. The thiol
group can then be reacted with a reactive dye in the presence of
sodium hydroxide to form a polymer attached dye colorant.
[0032] In another alternative embodiment of the present invention,
a dye can be attached to a monomer which can be subsequently
copolymerized to form a polymer in accordance with the present
invention. The polymers disclosed above can be suitable for such an
embodiment. For example, methacrylate functionalized dyes can be
copolymerized with monomers such as styrene, maleic anhydride,
acrylic acid, methacrylic acid, or the like. Examples of such
methacrylate functionalized dyes are described in more detail in
U.S. Patent Application Publication 2004/0024100, which is
incorporated herein by reference.
[0033] The extent of attachment of dye molecules to each polymer
chain can vary depending on reaction conditions, the polymer, and
the dye. However, as a general guideline, the dye to polymer chain
ratio can range from about 0.05 mmol/g to 10 mmol/g, and often from
about 1 mmol/g to about 5 mmol/g, i.e. mmol of dye molecules per
gram of polymer. Thus, the number of dye molecules per pigment
particle can range from about 10 .mu.mole dye molecules per gram of
pigment to about 100 mmole per gram of pigment, and in some cases
from about 0.05 mmole dye per gram of pigment to about 2 mmole per
gram pigment.
[0034] In one alternative embodiment, the polymer can include more
than one type of dye covalently attached thereto. Attachment of
additional dyes can be performed simultaneously with attachment of
a first dye, or can be attached in subsequent steps. Further, the
additional dyes can be substantially the same color as the first
dye. Such additional dyes can be used to affect any number of
properties such as dispersion stability, pH, lightfastness, cost,
and/or the like. Optionally, the additional dye(s) can have a
substantially different color than the first dye. For example, a
hue angle difference of 75 degrees or more would clearly indicate a
substantially different color. As a guideline, hue angle
differences are roughly 90 degrees from red to yellow, yellow to
green, and green to blue.
[0035] Many commonly known pigments can be covalently attached
using the polymers and methods of the present invention.
Specifically, various pigments can be functionalized with a
suitable chemical moiety which can be directly attached to the
polymer or attached to the polymer through a linking group. Such
methods of functionalizing pigments are known to those skilled in
the art. For example, U.S. Pat. Nos. 5,554,739; 5,707,432; and
5,851,280, and U.S. Patent Application Nos. 2003/0195291,
2003/0213410, 2003/0217672, and 2004/0007152 disclose methods of
functionalizing pigments using a number of methods, each of which
is hereby incorporated by reference in their entirety.
[0036] Non-limiting examples of common linking groups and
functional groups attached to pigments can include
2-(4-aminophenyl) sulfonylethane sulfonate, diazonium salt reaction
products, 4-aminobenzylamine, 4-aminophenylalanine, and other
nucleophilic groups. Optionally, certain polymers can be directly
attached to a functionalized pigment. For example, polymers
including an aminophenyl group could be directly attached to
pigments after diazotization. An example of such a polymer would be
a styrene acrylate polymer where some of the styrene monomers are
replaced by 4-aminostyrene, i.e. 4-vinylaniline. Frequently, it can
also be desirable to introduce a linking active group to the
polymer to facilitate attachment of the linking group thereto. For
example, the polymer can be reacted with 2-aminoethanethiol to form
a thiol group which can then be used to attach to the pigment
functionalized with 2-(4-aminophenyl) sulfonylethane sulfonate.
Other linking active groups can include, but is in no way limited
to, anhydrides, amines, or the like.
[0037] Although the exact ratio can vary somewhat, typically, the
pigment particle to polymer chain weight ratio can be from about
10:1 to 1:10. In addition, attachment of the dye to the polymer,
rather than directly to the pigment, allows for increased
availability of pigment surface area for polymeric dispersant
(either covalently attached or encapsulating), polymer-dye colorant
of the present invention, and/or other useful additives. Thus, the
amount of dye can be increased without decreasing the ability to
provide dispersant for stability of the pigment particles.
[0038] Suitable pigments can be black pigments, white pigments,
cyan pigments, magenta pigments, yellow pigments, or the like.
Further, pigments can be organic or inorganic particles as is well
known in the art. Suitable inorganic pigments include, for example,
carbon black. However, other inorganic pigments may be suitable
such as titanium oxide, cobalt blue (CoO--Al.sub.2O.sub.3), chrome
yellow (PbCrO.sub.4), and iron oxide. Suitable organic pigments
includes, for example, azo pigments including diazo pigments and
monoazo pigments, polycyclic pigments (e.g., phthalocyanine
pigments such as phthalocyanine blues and phthalocyanine greens,
perylene pigments, perynone pigments, anthraquinone pigments,
quinacridone pigments, dioxazine pigments, thioindigo pigments,
isoindolinone pigments, pyranthrone pigments, and quinophthalone
pigments), insoluble dye chelates (e.g., basic dye type chelates
and acidic dye type chelate), nitropigments, nitroso pigments, and
the like. Representative examples of phthalocyanine blues include
copper phthalocyanine blue and derivatives thereof (Pigment Blue
15). Representative examples of quinacridones include Pigment
Orange 48, Pigment Orange 49, Pigment Red 122, Pigment Red 192,
Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209,
Pigment Violet 19 and Pigment Violet 42. Representative examples of
anthraquinones include Pigment Red 43, Pigment Red 194 (Perinone
Red), Pigment Red 216 (Brominated Pyranthrone Red) and Pigment Red
226 (Pyranthrone Red). Representative examples of perylenes include
Pigment Red 123 (Vermillion), Pigment Red 149 (Scarlet), Pigment
Red 179 (Maroon), Pigment Red 190 (Red), Pigment Violet 19, Pigment
Red 189 (Yellow Shade Red) and Pigment Red 224. Representative
examples of thioindigoids include Pigment Red 86, Pigment Red 87,
Pigment Red 88, Pigment Red 181, Pigment Red 198, Pigment Violet
36, and Pigment Violet 38. Representative examples of heterocyclic
yellows include Pigment Yellow 1, Pigment Yellow 3, Pigment Yellow
12, Pigment Yellow 13, Pigment Yellow 14, Pigment Yellow 17,
Pigment Yellow 65, Pigment Yellow 73, Pigment Yellow 74, Pigment
Yellow 151, Pigment Yellow 117, Pigment Yellow 128 and Pigment
Yellow 138. Such pigments are commercially available in either
powder or press cake form from a number of sources including, BASF
Corporation, Engelhard Corporation and Sun Chemical
Corporation.
[0039] Examples of black pigments that can be used include carbon
pigments. The carbon pigment can be almost any commercially
available carbon pigment that provides acceptable optical density
and print characteristics. Carbon pigments suitable for use in the
present invention include, without limitation, carbon black,
graphite, vitreous carbon, charcoal, and combinations thereof. Such
carbon pigments can be manufactured by a variety of known methods
such as a channel method, a contact method, a furnace method, an
acetylene method, or a thermal method, and are commercially
available from such vendors as Cabot Corporation, Columbian
Chemicals Company, Degussa AG, and E.I. DuPont de Nemours and
Company. Suitable carbon black pigments include, without
limitation, Cabot pigments such as MONARCH 1400, MONARCH 1300,
MONARCH 1100, MONARCH 1000, MONARCH 900, MONARCH 880, MONARCH 800,
MONARCH 700, CAB-O-JET 200, CAB-O-JET 300, REGAL, BLACK PEARLS,
ELFTEX, MOGUL, and VULCAN pigments; Columbian pigments such as
RAVEN 7000, RAVEN 5750, RAVEN 5250, RAVEN 5000, and RAVEN 3500;
Degussa pigments such as Color Black FW 200, RAVEN FW 2, RAVEN FW
2V, RAVEN FW 1, RAVEN FW 18, RAVEN S160, RAVEN FW S170, Special
Black 6, Special Black 5, Special Black 4A, Special Black 4,
PRINTEX U. PRINTEX 140U, PRINTEX V, and PRINTEX 140V; and TIPURE
R-101 available from Dupont. The above list of pigments includes
unmodified pigment particulates, small molecule attached pigment
particulates, and polymer-dispersed pigment particulates.
[0040] Similarly, a wide variety of colored pigments can be used
with the present invention, therefore the following listing is not
intended to be limiting. For example, colored pigments can be blue,
brown, cyan, green, white, violet, magenta, red, orange, yellow, as
well as mixtures thereof. The following color pigments are
available from Cabot Corp.: CABO-JET 250C, CABO-JET 260M, and
CABO-JET 270Y. The following color pigments are available from BASF
Corp.: PALIOGEN Orange, PALIOGEN Orange 3040, PALIOGEN Blue L 6470,
PALIOGEN Violet 5100, PALIOGEN Violet 5890, PALIOGEN Yellow 1520,
PALIOGEN Yellow 1560, PALIOGEN Red 3871K, PALIOGEN Red 3340,
HELIOGEN Blue L 6901F, HELIOGEN Blue NBD 7010, HELIOGEN Blue K
7090, HELIOGEN Blue L 7101F, HELIOGEN Blue L6900, L7020, HELIOGEN
Blue D6840, HELIOGEN Blue D7080, HELIOGEN Green L8730, HELIOGEN
Green K 8683, and HELIOGEN Green L 9140. The following pigments are
available from Ciba-Geigy Corp.: CHROMOPHTAL Yellow 3G, CHROMOPHTAL
Yellow GR, CHROMOPHTAL Yellow 8G, IGRAZIN Yellow 5GT, IGRALITE
Rubine 4BL, IGRALITE Blue BCA, MONASTRAL Magenta, MONASTRAL
Scarlet, MONASTRAL Violet R, MONASTRAL Red B, and MONASTRAL Violet
Maroon B. The following pigments are available from Heubach Group:
DALAMAR Yellow YT-858-D and HEUCOPHTHAL Blue G XBT-583D. The
following pigments are available from Hoechst Specialty Chemicals:
Permanent Yellow GR, Permanent Yellow G, Permanent Yellow DHG,
Permanent Yellow NCG-71, Permanent Yellow GG, Hansa Yellow RA,
Hansa Brilliant Yellow 5GX-02, Hansa Yellow-X, NOVOPERM Yellow HR,
NOVOPERM Yellow FGL, Hansa Brilliant Yellow 10GX, Permanent Yellow
G3R-01, HOSTAPERM Yellow H4G, HOSTAPERM Yellow H3G, HOSTAPERM
Orange GR, HOSTAPERM Scarlet GO, HOSTAPERM Pink E, Permanent Rubine
F6B, and the HOSTAFINE series. The following pigments are available
from Mobay Corp.: QUINDO Magenta, INDOFAST Brilliant Scarlet,
QUINDO Red R6700, QUINDO Red R6713, and INDOFAST Violet. The
following pigments are available from Sun Chemical Corp.: L74-1357
Yellow, L75-1331 Yellow, and L75-2577 Yellow. Other examples of
pigments can include Normandy Magenta RD-2400, Permanent Violet
VT2645, Argyle Green XP-111-S, Brilliant Green Toner GR 0991, Sudan
Blue OS, PV Fast Blue B2GO1, Sudan III, Sudan II, Sudan IV, Sudan
Orange G, Sudan Orange 220, Ortho Orange OR 2673, Lithol Fast
Yellow 0991 K, Paliotol Yellow 1840, Lumogen Yellow D0790,
Suco-Gelb L1250, Suco-Yellow D1355, Fanal Pink D4830, Cinquasia
Magenta, Lithol Scarlet D3700, Toluidine Red, Scarlet for
Thermoplast NSD PS PA, E. D. Toluidine Red, Lithol Rubine Toner,
Lithol Scarlet 4440, Bon Red C, Royal Brilliant Red RD-8192, Oracet
Pink RF, and Lithol Fast Scarlet L4300. These pigments are
available from commercial sources such as Hoechst Celanese
Corporation, Paul Uhlich, BASF, American Hoechst, Ciba-Geigy,
Aldrich, DuPont, Ugine Kuhlman of Canada, Dominion Color Company,
Magruder, and Matheson. Examples of other suitable colored pigments
are described in the Colour Index, 3rd edition (The Society of
Dyers and Colourists, 1982).
[0041] Other pigments not specifically listed can also be suitable
for attachment to the polymers based on the disclosure provided
herein. The above-illustrated pigments can be used singly or in
combination of two or more. Typically, the pigments of the present
invention can be from about 10 nm to about 10 .mu.m and in one
aspect can be from 10 nm to about 500 nm in diameter, although
sizes outside this range can be used if the pigment can remain
dispersed and provide adequate color properties. In one detailed
aspect of the present invention, the pigment can comprise from
about 1% to about 20% by weight of the ink-jet ink composition, and
often can comprise from about 2% to about 5% by weight of the
ink-jet ink composition.
[0042] Frequently, the pigment and the dye can have substantially
the same color. In this way, the polymeric colorant can have
improved chroma resulting from the presence of dye, while also
improving lightfastness, waterfastness, and permanence as a result
of the pigment. In one alternative aspect of the present invention,
the pigment can be a different color than the dye. For example, the
pigment can have a black color and the dye can have a cyan or
magenta color such that the polymeric colorant has an effective
color which is a neutral gray. Alternatively, both cyan and magenta
dyes can be covalently attached to the same polymer or separate
polymers which are then attached to the same pigment. Thus, as a
general matter, more than one type of dye can be attached to the
same polymer chains. Additionally, more than one type of polymer
and or polymer-dye combinations can be attached to the pigment
particles.
[0043] The polymeric colorants of the present invention can further
include a dispersant attached thereto. Suitable dispersants can be
attached to the pigment, the polymer, and/or the dye. In one
specific embodiment, the dispersant can be attached to the pigment.
Attaching the polymer to the pigment in accordance with the present
invention in many cases provides additional room for attachment of
a dispersant directly to the pigment. In other embodiments, it can
be desirable to attach dispersant to the polymer. In order to
attach dispersant to the polymer, reactive groups similar to those
used for attachment of the dye can be useful. Further, the
dispersant can be attached simultaneously with the dye, or in a
separate step. Generally, the order of attachment of the dye,
dispersant, and the pigment can be adjusted to suit a particular
manufacturing design. Often, the order of attachment is not
critical; however, most often the pigment can be attached in a
final processing step to a polymer-dye colorant having a dispersant
attached thereto. Most often, the reactive group can be a
carboxylic acid, however, reactive groups such as hydroxy, amino,
anhydride, sulfonic acid, thiol, halotriazine, maleimide and vinyl
sulfone, or the like can also be used.
[0044] A wide variety of dispersants are known to those skilled in
the art which can also be useful for attachment to the polymeric
dyes of the present invention. Non-limiting examples broad classes
of suitable dispersants include polyalkyl glycols, polyalkyl
imines, aryl dicarboxylic acids such as phthalic acids, isophthalic
acids, terephthalic acids, carbohydrates, acrylates, methacrylates,
trehalose, isomers thereof, and combinations thereof. As a general
matter, glycol dispersants tend to be stable at neutral and higher
pH, while imine dispersants tend to be stable at lower pH, e.g.,
about 4-6. In one specific embodiment, the dispersant can be
polyethylene glycol. Dispersants can help to improve dispersion
stability, but also can improve bleed control. Non-limiting
examples of several specific suitable dispersants include
polypropylene glycol, polyethylene imine, polyethylene glycol,
trehalose, and combinations thereof. In some embodiments, the
polymer having a dye attached thereto can also be a dispersant,
such that the pigment is polymer-dispersed.
[0045] In an additional optional embodiment of the present
invention, the polymeric colorant can include various stabilizing
additives. Such stabilizing additives can be any functional group
which provides improved lightfastness, ozone fastness, steric
stabilization, electrostatic stabilization, or the like. Specific
non-limiting examples of suitable stabilizing additives include PEG
(steric stabilization and improving solubility of certain dyes),
carbohydrates (steric stabilization), polyethylene imine
(electrosteric stabilization generally at acidic pH), acrylates
(electrosteric stabilization generally at high pH), or the like. An
additional benefit of the present invention is to provide improved
protection of the dye from light fade and/or degradation due to
exposure to air. This can be at least partially due to a majority
of the dye being embedded in the polymer to which it is attached
and embedded by neighboring polymer chains.
[0046] As a general matter, polymeric colorants of the present
invention can have the structure as described above. However, in
one specific embodiment, the polymeric colorant can have the
general structure shown in Formula 1, which is based on maleic
anhydride copolymers. ##STR1## where x, y, and z are non-zero
positive integers such that the polymer has a molecular weight less
than about 20,000; R1 is the dye, the dispersant, or a linking
group attached to the pigment with the proviso that z is at least
three and at least one of each of the dye, the dispersant, and the
linking group is present; and R2 is a hydrophobic group. It will be
understood that the above structure does not necessarily indicate a
block copolymer. Rather, for convenience the polymeric units are
segregated and actual embodiments can be random copolymers, block
copolymers, or any other arrangement of the monomeric units shown.
R2 can be provided using any number of hydrophobic monomers such as
styrene, 4-alkylstyrene, alkyl acrylates, methacrylates, methyl
vinyl ether, alkyl vinyl ether, vinyl acetate, vinyl pyrrolidone,
or the like. Further, when using maleic anhydride copolymers as
shown in Formula 1, the monomeric units of group z are generally
provided by reaction of the R1 group, i.e. dye, additive, or
dispersant, with the anhydride portion of the maleic anhydride.
Thus, the original number of maleic anhydride units is reduced by
z, leaving y units of maleic anhydride during manufacture of the
polymeric colorants of the present invention.
[0047] In yet another more detailed aspect, the polymeric colorant
can have the general structure: ##STR2## where a, b, and c are
non-zero positive integers such that the polymer has a molecular
weight less than about 20,000. Ink-Jet Ink Compositions
[0048] The polymeric colorants of the present invention can be used
in a wide variety of applications such as, but not limited to, ink
compositions, molded articles, or the like. In one aspect, the
polymeric colorants of the present invention can be included as
part of an ink-jet ink composition. As such, the polymeric
colorant, as described herein, can be dispersed in an appropriate
liquid vehicle.
[0049] In yet another alternative embodiment, an ink-jet ink
composition can include a liquid vehicle, a polymer attached dye,
and a pigment. In this embodiment, the polymer attached dye can
include a dye covalently attached to a polymer, with the dye having
a first color. The pigment can have a second color which is
substantially different in hue from the first color.
[0050] In such cases, the pigment is not necessarily attached to
the dye and can be dispersed in accordance with known principles.
Thus, the pigment can be polymer-dispersed, self-dispersed, or
covalently attached to the polymer attached dye to form a polymeric
colorant. In a further detailed aspect of this embodiment, the
polymer can have at least two different dyes covalently attached to
the polymer. In one aspect, the dye color can be cyan, magenta, or
yellow and the pigment color can be black.
[0051] Ink-jettable ink compositions of the present invention are
typically prepared in an aqueous formulation or ink vehicle which
can include water, cosolvents, surfactants, buffering agents,
biocides, sequestering agents, viscosity modifiers, humectants,
binders, plasticizers, fixers, and/or other known additives.
Further, the present invention can be used in conjunction with
reactive ink sets for enhanced bleed control. Typically, the
ink-jet ink compositions of the present invention can have a
viscosity of between about 0.8 to about 8 cps. In one aspect of the
present invention, the ink vehicle can comprise from about 70% to
about 98% by weight of the ink-jet ink composition.
[0052] As described, cosolvents can be included in the ink-jet
compositions of the present invention. Suitable cosolvents for use
in the present invention include water soluble organic cosolvents,
but are not limited to, aliphatic alcohols, aromatic alcohols,
diols, glycol ethers, poly(glycol) ethers, lactams, formamides,
acetamides, long chain alcohols, ethylene glycol, propylene glycol,
diethylene glycols, triethylene glycols, glycerine, dipropylene
glycols, glycol butyl ethers, polyethylene glycols, polypropylene
glycols, amides, ethers, carboxylic acids, esters, organosulfides,
organosulfoxides, sulfones, alcohol derivatives, carbitol, butyl
carbitol, cellosolve, ether derivatives, amino alcohols, and
ketones. For example, cosolvents can include primary aliphatic
alcohols of 30 carbons or less, primary aromatic alcohols of 30
carbons or less, secondary aliphatic alcohols of 30 carbons or
less, secondary aromatic alcohols of 30 carbons or less, 1,2-diols
of 30 carbons or less, 1,3-diols of 30 carbons or less, 1,5-diols
of 30 carbons or less, ethylene glycol alkyl ethers, propylene
glycol alkyl ethers, poly(ethylene glycol) alkyl ethers, higher
homologs of poly(ethylene glycol) alkyl ethers, poly(propylene
glycol) alkyl ethers, higher homologs of poly(propylene glycol)
alkyl ethers, lactams, substituted formamides, unsubstituted
formamides, substituted acetamides, and unsubstituted acetamides.
Specific examples of cosolvents that are preferably employed in the
practice of this invention include, but are not limited to,
1,5-pentanediol, 2-pyrrolidone,
2-ethyl-2-hydroxymethyl-1,3-propanediol, diethylene glycol,
3methoxybutanol, and 1,3-dimethyl-2-imidazolidinone. Cosolvents can
be added to reduce the rate of evaporation of water in the ink to
minimize clogging or other properties of the ink such as viscosity,
pH, surface tension, optical density, and print quality. The
cosolvent concentration can range from about 0% to about 50 wt
%.
[0053] Various buffering agents can also be optionally used in the
ink-jet ink compositions of the present invention. Typical
buffering agents include such pH control solutions as hydroxides of
alkali metals and amines, such as lithium hydroxide, sodium
hydroxide, potassium hydroxide; citric acid; amines such as
triethanolamine, diethanolamine, and dimethylethanolamine; and
other basic or acidic components which do not interfere with the
colorant characteristics of the present invention. If used,
buffering agents typically comprise less than about 10% by weight
of the ink-jet ink composition.
[0054] In another aspect of the present invention, various biocides
can be used to inhibit growth of undesirable microorganisms.
Several non-limiting examples of suitable biocides include benzoate
salts, sorbate salts, commercial products such as NUOSEPT (Nudex,
Inc., a division of Huls America), UCARCIDE (Union Carbide),
VANCIDE (RT Vanderbilt Co.), and PROXEL (ICI Americas) and other
known biocides. Typically, such biocides comprise less than about
5% by weight of the ink-jet ink composition and often from about
0.1% to about 0.25% by weight.
[0055] In an additional aspect of the present invention, binders
can be included which act to secure the polymeric colorants on the
substrate. Binders suitable for use in the present invention
typically have a molecular weight of from about 100 to about 50,000
g/mol. Non-limiting examples include polyester, polyester-melanine,
styrene-acrylic acid copolymers, styrene-acrylic acid-alkyl
acrylate copolymers, styrene-maleic acid copolymers, styrene-maleic
acid-alkyl acrylate copolymers, styrene-methacrylic acid
copolymers, styrene-methacrylic acid-alkyl acrylate copolymers,
styrene-maleic half ester copolymers, vinyl naphthalene-acrylic
acid copolymers, vinyl naphthalene-maleic acid copolymers, and
salts thereof.
[0056] Standard water-soluble surfactants can also be optionally
used such as alkyl polyethylene oxides, alkyl phenyl polyethylene
oxides, polyethylene oxide (PEO) block copolymers, acetylenic PEO,
PEO esters, PEO amines, PEO amides, and dimethicone copolyols. Some
of these materials are available commercially under the tradenames
TERGITOL, SURFYNOL, ZONYL, TRITON, MERPOL, and the like. If used,
surfactants can be from 0.01% to about 10% by weight of the ink-jet
ink composition.
[0057] Once the ink-jet ink compositions are prepared, they can be
placed into one or more ink-jet pens as is well known in the art.
In one detailed aspect of the present invention, a system for
printing images on a substrate in accordance with the present
invention can include at least one firing chamber containing
ink-jet ink compositions, respectively, to form an ink-jet pen.
Typical ink-jet pens can have an orifice plate having a plurality
of orifices through which the ink-jet ink composition can be
delivered to a substrate using thermal, piezoelectric, or other
known ink-jet technologies.
EXAMPLES
[0058] The following examples illustrate the embodiments of the
invention that are presently best known. However, it is to be
understood that the following are only exemplary or illustrative of
the application of the principles of the present invention.
Numerous modifications and alternative compositions, methods, and
systems may be devised by those skilled in the art without
departing from the spirit and scope of the present invention. The
appended claims are intended to cover such modifications and
arrangements. Thus, while the present invention has been described
above with particularity, the following Examples provide further
detail in connection with what are presently deemed to be the most
practical and preferred embodiments of the invention.
Example 1
[0059] C.I. Acid Red 440 dye can be attached to styrene maleic
anhydride polymer (SMA 1000) as follows. To 1 liter of dry DMF in a
flask under a nitrogen atmosphere is added 110 g (544 mmole
anhydride) of SMA 1000. The suspension can be heated to 50.degree.
C. with stirring to give a clear solution. To this solution under
nitrogen is added 80.4 g (220 mmole) of AR 440 dye, 22.3 g (220
mmole) of triethylamine and 2.7 g (22 mmole) of
dimethylaminopyridine. The mixture is stirred for at least 4 hours
at this temperature. To this mixture is added 36.4 g (320 mmole) of
2-aminoethanethiol hydrochloride followed by 64.8 g (640 mmole) of
triethylamine. The mixture is stirred overnight while it cools down
to room temperature under a nitrogen atmosphere. The mixture is
then added to an excess of ice cold 1 N hydrochloric acid. This
results in precipitation of a bluish red polymer-dye conjugate. The
precipitate is filtered and washed several times with 1 N HCl
followed by deionized water. The mixture is then dried in a vacuum
desiccator at room temperature.
[0060] Conjugation of the above dye-polymer conjugate to pigment
red 122 is accomplished as follows. To a stirred solution of 100 mL
of 1 N NaOH under nitrogen is added 20 g of the polymer-dye
conjugate described above. The mixture is heated to 50.degree. C.
to ensure complete dissolution. To the clear magenta solution is
added 400 g of a 10% aqueous dispersion of pigment red 122 having
been modified with 2-(4-aminophenyl) sulfonylethane sulfonate. The
pH is raised to about 12-13 by an additional 25 ml of 1 N NaOH and
the mixture will is stirred overnight at room temperature under a
nitrogen atmosphere. The resultant dispersion is capped with sodium
acrylate and purified by diafiltration.
Example 2
[0061] To 1 liter of dry DMF in a reaction flask under a nitrogen
atmosphere is added 110 g (544 mmole anhydride) of SMA 1000. The
suspension is heated to 50.degree. C. while stirring to give a
clear solution. To this solution is added 45.4 g (400 mmole) of
2-aminoethanethiol hydrochloride and 100 g (100 mmole) of JEFFAMINE
XTJ506 (a polyoxyalkyleneamine dispersant available from Huntsman
Corporation) and the mixture is stirred under nitrogen atmosphere
for about 30 minutes. Then 101.2 g (1 mole) of triethylamine is
added in a dropwise fashion. The mixture is then allowed to cool to
room temperature and stirred overnight under a nitrogen atmosphere.
The mixture is then added to an excess of ice cold 1 N hydrochloric
acid. This results in a white polymer precipitate. The precipitate
is filtered and washed several times with 1 N HCl followed by
deionized water. The mixture is then dried in a vacuum desiccator
at room temperature.
[0062] To a stirred solution of 700 mL of 1 N NaOH under nitrogen
is added 140 g of the modified SMA polymer described above. The
mixture is heated to 50.degree. C. to ensure complete dissolution.
To the solution is added 502 g (80 mmole) of a 10% aqueous solution
of reactive blue 19 dye over 10 minutes. The pH is raised to 12-13
by addition of 150 ml of 1 N NaOH and the mixture is stirred
overnight at room temperature under a nitrogen atmosphere. The
mixture is then added to an excess of ice cold 1 N hydrochloric
acid. This results in a blue precipitate of dye-polymer conjugate.
The precipitate is filtered and washed several times with 1 N HCl
followed by deionized water. The mixture is then dried in a vacuum
desiccator at room temperature.
[0063] Conjugation of the above dye-polymer conjugate to carbon
black pigment can be accomplished as follows. To a stirred solution
of 100 mL of 1 N NaOH under nitrogen is added 20 g of the
dye-polymer conjugate described above. The mixture is heated to
50.degree. C. to ensure complete dissolution. To the clear blue
solution is added 400 g of a 10% aqueous dispersion of carbon black
having been modified with 2-(4-aminophenyl) sulfonylethane
sulfonate. The pH is raised to 12-13 by the addition of 25 ml of 1
N NaOH and the mixture is stirred overnight at room temperature
under nitrogen atmosphere. The resultant dispersion is capped with
sodium acrylate and purified by diafiltration.
[0064] It is to be understood that the above-referenced
arrangements are illustrative of the application for the principles
of the present invention. Numerous modifications and alternative
arrangements can be devised without departing from the spirit and
scope of the present invention while the present invention has been
shown in the drawings and described above in connection with the
exemplary embodiments(s) of the invention. It will be apparent to
those of ordinary skill in the art that numerous modifications can
be made without departing from the principles and concepts of the
invention as set forth in the claims.
* * * * *